Faculty Collaboration Database

Estimating FVC from FEV2 and FEV3: assessment of a surrogate spirometric parameter. Chest 2005 Sep;128(3):1274-81

Date

09/16/2005

Pubmed ID

16162718

DOI

10.1378/chest.128.3.1274

Scopus ID

2-s2.0-24944452224 (requires institutional sign-in at Scopus site)   14 Citations

Abstract

BACKGROUND: In the context that accurate measurement of FVC is important in diagnosing airflow obstruction and in assessing restriction, strategies to achieve reliable and accurate FVC measurement have drawn much attention.

OBJECTIVES: Because the rate of achieving end-of-test criteria during spirometry has been shown to be low, with resultant under-recording of the FVC, the current study proposes a regression equation for estimating FVC from measured values of the forced expiratory volume in 2 s (FEV2) and forced expiratory volume in 3 s (FEV3).

METHODS: The predictive equation for the estimated FVC from volume measurements within the first 3 s of exhalation (estimated FVC3) was generated based on 330 consecutive acceptable spirograms performed in the Cleveland Clinic Foundation Pulmonary Function Laboratory. The equation was applied to an independent validation set comprised of spirometry measurements on 370 different consecutive patients.

RESULTS: In the validation spirometry sample, in which the prevalence of obstruction was 34% (based on values of the measured FEV1/FVC compared to National Health and Nutrition Examination Survey III values), the sensitivity, specificity, and positive and negative predictive values of FEV1/estimated FVC3 for obstruction were 93.8%, 89.1%, 81.2%, and 96.9%, respectively. The misclassification rate was 9.2%. In the same cohort, the mean difference (+/- SD) between estimated FVC3 and measured FVC was 24.7 +/- 237 mL.

CONCLUSIONS: Given that FVC is frequently under-recorded, with resultant overestimation of FEV1/FVC and underdiagnosis of airflow obstruction, we believe that estimating FVC from FEV2 and FEV3 can offer practical diagnostic advantages.

Author List

Ioachimescu OC, Venkateshiah SB, Kavuru MS, McCarthy K, Stoller JK

Author

Octavian C. Ioachimescu MD, PhD Vice Chair, Director, Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Aged
Airway Obstruction
Cohort Studies
Female
Forced Expiratory Volume
Humans
Lung Diseases
Male
Middle Aged
Models, Biological
Predictive Value of Tests
Spirometry
Vital Capacity